<!DOCTYPE html>
<html>

<head>
	<meta charset="UTF-8">
	<title>Bootstrap 实例</title>

    <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/4.0.0-beta/css/bootstrap.min.css" integrity="sha384-/Y6pD6FV/Vv2HJnA6t+vslU6fwYXjCFtcEpHbNJ0lyAFsXTsjBbfaDjzALeQsN6M" crossorigin="anonymous">
	
</head>

<body>
	<section class="container">
		<div class="card my-4">
			<div class="card-header"><h5 class="text-primary"></h5></div>
			<div class="card-body">

			</div>
		</div>
	</section>

<script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script>
<script src="https://cdn.bootcss.com/popper.js/1.12.5/umd/popper.min.js"></script>
<script src="https://cdn.bootcss.com/bootstrap/4.0.0-beta/js/bootstrap.min.js"></script>
</body>

</html>